From manufacturing an optical fibre, a certain length of said optical fibre is wound on a bobbin in view of its storage and its transport to a place of use. This length is typically around a few kilometres.
In view of being able to test a sample of optical fibre from said bobbin, it is known to wind an excess length of optical fibre onto a dedicated magazine arranged in the bobbin. This excess length corresponding to a section of the optical fibre first wound onto the bobbin, such a magazine allows making this excess length accessible after winding the whole of the fibre.
FIG. 1A is a perspective view of a bobbin 1′, of known type, comprising such a magazine.
The bobbin 1′ comprises a cylindrical reel 10 to receive the optical fibre, and two rims 11, 12 which extend radially to each end of the reel 10 in order to axially retain the optical fibre wound onto the reel.
One of the two rims (in this case, the rim 11) is provided with a port 110 for the optical fibre 100.
Said rim 11 separates the reel 10 from a cylindrical magazine 13 which is intended to receive an excess length 100′ of optical fibre.
As can be best seen in FIG. 1B, the rim has a circumferential edge 130 to axially retain the excess length 100′ of optical fibre wound onto the magazine.
To wind an excess length 100′ of optical fibre onto the magazine, an operator passes a section 100′ of optical fibre of the desired length through the port 110 (from the reel towards the magazine) then manually winds this section of optical fibre onto the magazine 13, behind the circumferential edge 130. Then, to avoid any unintentional unwinding of the optical fibre, he attaches the end 100″ of this onto the rim 11 by means of an adhesive 101.
This manual operation takes a long time and is costly.
The document JP 2015-010031 discloses a method for automatically winding an excess length of optical fibre onto the magazine of a bobbin. To this end, the bobbin is provided with a removable plate which is inserted onto the circumferential edge of the magazine to as to wedge the free end of the optical fibre before it is wound onto the magazine.
However, this method has the disadvantage that the free end of the optical fibre is located on the internal side of the winding (in other words, close to the cylindrical surface), so that the later unwinding of a section of said excess length is difficult to implement without damaging the optical fibre. Furthermore, it requires an additional component to be added to the bobbin to wedge the free end of the optical fibre.